Not applicable
Not applicable
Not applicable
1. Field of the Invention
The invention relates to communication networks, and specifically, to a method and system for providing continuity testing and call tones in a communication network.
2. Description of the Prior Art
The development of advanced communication networks has taken on critical importance with the dramatic rise in consumer demand for: higher quality services. Continuity testing in communication networks is one method of ensuring the quality of services. A continuity test ensures bearer channel connectivity prior to call completion. The continuity test is generally performed on a pre-determined percentage, of calls to verify bearer channel connectivity between a pair of switches.
FIG. 1 illustrates an example of a continuity test in a public switched telephone network (PSTN) using signaling system 7 (SS7). On FIG. 1 the calling party removes the receiver from the calling party""s telephone 100. The originating switch 101 detects the off-hook and provides a dial tone to telephone 100. Responsive to receiving the dial tone, the user enters the digits for a call destination. The originating switch 101 processes the entered digits and provides an initial address message (LAM) to the network 102. The IAM message includes a continuity test flag that indicates to the network 102 that a continuity test will be performed on the bearer channel between the network 102 and the originating switch 101. The originating switch 101 then sends a test tone over the bearer channel to the network 102. Responsive to sending the test tone, the originating switch 101 starts a timer. The network 102 loops the test tone back to the originating switch 101. If the test tone is received back in the originating switch 101 before the timer times-out, the continuity test is successful and the originating switch 101 sends a continuity message to the network 102. The continuity message confirms the continuity test is complete and successful. If the test tone is not received back in the originating switch 101 before the timer times-out, the continuity test is failed and the call is cleared Responsive to a successful continuity test, the network 102 provides an IAM message to the terminating switch 103 and reserves a call connection between the originating switch 101 and the terminating switch 103. The terminating switch 103 sends an address complete message (ACM) to the network 102 and the call is completed between telephones 100 and 104 in the conventional fashion.
Call tones are generated in communication networks to provide callers with feedback regarding the status of calls and call connections. Examples of specific call tones include a ringback tone, a busy signal tone, and a reorder tone. The reorder tone is sometimes referred to as a fast busy signal in the art. Typically, call tones are provided in communication networks by a terminating communication device upon completion of the call connection. In some applications however, call tones can be provided by an originating communication device by triggering the call tone generation using a control or signaling channel.
FIG. 1 illustrates an example of call tone control and generation for a call session in the PSTN 102. On FIG. 1 the calling party removes the receiver from the calling party""s telephone 100. The originating switch 101 detects the off-hook and provides a dial tone to the calling party""s telephone 100. Responsive to receiving the dial tone, the user enters the digits for a call destination. The originating switch 101 processes the entered digits and provides a call setup message to the network 102. The network 102 provides the call setup message to the terminating switch 103 and reserves a connection between the originating switch 101 and the terminating switch 103. In response to receiving the call setup message, the terminating switch 103 provides an acknowledgment message to the network 102. If the terminating switch 103 detects the called party""s telephone 104 is off-hook or busy, the terminating switch 103 provides busy signal tones over the network 102 to the calling pasty""s telephone 100. If the terminating switch 103 does not detect that the called party""s telephone 104 is off-hook or busy, the terminating switch 103 provides ringback tones over the network 102 to the calling party""s telephone 100. The terminating switch 103 also rings the called party""s telephone 104 to announce the incoming call.
FIG. 2 illustrates another example of call tone generation and control for a call session in a packet communication network. On FIG. 2 the calling party removes the receiver from the calling party""s telephone 200. The originating communication hub 201 detects the off-hook event and provides an off-hook message to the network 202. Responsive to receiving the off-hook message, the network 202 provides a dial tone to the calling party""s telephone 200 via the originating communication hub 201. Responsive to receiving the dial tone the user enters the digits for the call destination. The originating communication hub 201 detects the digits and provides the digits to the network 202. The network 202 processes the digits and generates a setup message for a terminating communication hub 203 connected to the called party""s telephone 204. Responsive to receiving the setup message, the terminating communication hub 203 provides a setup acknowledgment message to the network 202. If the called party""s telephone 204 is off-hook or busy, the terminating communication hub 203 provides busy signal tones over the network 202 and communication hub 201 to the calling party""s telephone 200. If the terminating communication hub 203 does not detect the called party""s telephone 203 is off-hook or busy, the terminating communication hub 203 provides ringback tones over the network 202 and communication hub 201 to the calling party""s telephone 200. The terminating communication hub 203 also rings the called party""s telephone 204 to announce the incoming, call.
It is a problem in communication networks to provide call tones over the network from the terminating device. New services such as call waiting, call forwarding, and three-way-calling have increased network resource demands. Therefore, a need exists in the art to free network resources currently utilized by call tone generation and control in communication networks. It is also a problem to provide continuity testing in packet networks. Unfortunately, packet-networks do not effectively support continuity testing.
The present invention advances the art by providing a communication hub that provides call tones in communication networks at points proximate the calling device and performs continuity testing to ensure bearer path connectivity prior to call completion. Some examples of call tones that could be provided include without limitation, ringback tones, busy signal tones, and reorder tones. Advantageously, in some examples of the invention, the communication hub combines call tone generation and control with continuity testing in the network and utilizes the call tone messaging to perform the continuity test. Advantageously, network resources required for call completion are reduced because call tones are provided at points proximate the calling device and a separate continuity test of the bearer channel is unnecessary. Also advantageously, service assurance is provided before call completion and early detection of network failures is realized.
The communication hub is comprised of a processor, an interface, and a tone generator. The tone generator is configured to generate the call tones under control of the processor. The processor is configured to process an in-band call tone request message that includes a request to provide call tones to a call device connected to the communication hub. The processor is further configured to generate a continuity acknowledgment message in response to the call tone request message and direct the tone generator to provide call tones to the call device. The interface is configured to receive the call tone request message and transmit the continuity acknowledgment message and the call tones.
In the context of the present invention the first, second, third, fourth, etc. connotations used to reference the messages, the calls, and the devices are used for the purpose of differentiating between different messages, different calls, and different devices and are not used to indicate a message sequence, call sequence or processing sequence. Also in the context of the present invention, an on-network call session is defined as a call session between two devices connected to the same communication network. An off-network to on-network call session and an on-network to off-network call session are defined as an incoming call session and an outgoing call session, respectively, between two devices connected to different communication networks, e.g., an incoming call session or an outgoing call session between a call device, connected to a packet network and a call device connected to the PSTN. In-band is defined as using the bearer portion of a communication path, for example, in an asynchronous transfer mode network over the bearer channel. Those skilled in the art will appreciate that in some environments, such as an Internet Protocol (IP) environment, in-band could be an address of an originating device and terminating device.